// panel_worktrees.cpp — lists git worktrees via `git worktree list --porcelain`.
//
// Read-only MVP: shows path, head, branch. Future work: create/remove from
// inside the panel (TODO in app.md ## Gotchas).
#include "panels.h"
#include "core/icons_tabler.h"

#include <imgui.h>
#include <cstdio>
#include <string>
#include <vector>
#include <array>

namespace kanban_cpp {

namespace {

struct WT {
    std::string path;
    std::string head;
    std::string branch;
};

std::vector<WT> scan_worktrees() {
    std::vector<WT> out;
#ifdef _WIN32
    FILE* fp = _popen("git worktree list --porcelain 2>nul", "r");
#else
    FILE* fp = popen("git worktree list --porcelain 2>/dev/null", "r");
#endif
    if (!fp) return out;
    std::array<char, 1024> buf;
    WT cur;
    while (std::fgets(buf.data(), static_cast<int>(buf.size()), fp)) {
        std::string line(buf.data());
        while (!line.empty() && (line.back() == '\n' || line.back() == '\r')) line.pop_back();
        if (line.empty()) {
            if (!cur.path.empty()) out.push_back(cur);
            cur = WT();
            continue;
        }
        if (line.rfind("worktree ", 0) == 0) cur.path   = line.substr(9);
        else if (line.rfind("HEAD ", 0) == 0) cur.head   = line.substr(5);
        else if (line.rfind("branch ", 0) == 0) cur.branch = line.substr(7);
    }
    if (!cur.path.empty()) out.push_back(cur);
#ifdef _WIN32
    _pclose(fp);
#else
    pclose(fp);
#endif
    return out;
}

} // namespace

void draw_worktrees(AppState& /*s*/, bool* p_open) {
    if (!ImGui::Begin(TI_GIT_BRANCH " Worktrees", p_open)) {
        ImGui::End();
        return;
    }

    static std::vector<WT> wts;
    static bool first = true;
    if (first) { wts = scan_worktrees(); first = false; }
    if (ImGui::Button(TI_REFRESH " Rescan")) wts = scan_worktrees();
    ImGui::SameLine();
    ImGui::TextDisabled("%zu worktrees", wts.size());
    ImGui::Separator();

    if (ImGui::BeginTable("##wts", 3, ImGuiTableFlags_Borders | ImGuiTableFlags_RowBg)) {
        ImGui::TableSetupColumn("Branch");
        ImGui::TableSetupColumn("HEAD");
        ImGui::TableSetupColumn("Path");
        ImGui::TableHeadersRow();
        for (const auto& w : wts) {
            ImGui::TableNextRow();
            ImGui::TableSetColumnIndex(0);
            ImGui::TextUnformatted(w.branch.empty() ? "(detached)" : w.branch.c_str());
            ImGui::TableSetColumnIndex(1);
            ImGui::TextUnformatted(w.head.substr(0, 10).c_str());
            ImGui::TableSetColumnIndex(2);
            ImGui::TextUnformatted(w.path.c_str());
        }
        ImGui::EndTable();
    }

    ImGui::End();
}

} // namespace kanban_cpp